Automatic luminous traffic signal apparatus



Dec. 17, 1957 A. c. FREIRE AUTOMATIC LUMINOUS TRAFFIC SIGNAL APPARATUS Filed June 10, 1954 2 Sheets-Sheet 1 INVENTOR. Cu/YHA Fgems' Dec. 17, 1957 A. C. FREIRE AUTOMATIC LUMINOUS TRAFFIC SIGNAL APPARATUS Filed June 10, 1954 2 Sheets-Sheet 2 INVENTOR. nl'm'o JM/ BY 31m] A TTOR N E g United States Patent AUTOMATIC LUMINOUS TRAFFIC SIGNAL APPARATUS Antonio Cunha Freire, Sao Paulo, Brazil Application June 10, 1954, Serial No. 435,851

Claims priority, application Brazil July 3, 1953 6 Claims. (Cl. 340-43) The present invention relates to trafi'ic signal apparatus.

More particularly, the present invention relates to an automatic luminous traflic signal apparatus which, as existing signal devices, emits red and green signals alternately. However, a trafiic signal apparatus according to the present invention makes it possible for the observer to know exactly how much time remains before the green light changes to red, i. e. the observer will at all times know exactly how much time remains before the green light will be extinguished and the red light turned on. Consequently, in a traffic control apparatus according to the present invention there is no need for any visual or audible indication which announces the imminent appearance of the red light.

It is therefore an object of the present invention to provide an automatic traffic signal apparatus which is capable of fulfilling the above mission.

It is another object of the present invention to provide a traffic signal apparatus which may be constructed at low cost.

The objects of the present invention also include the provision of an automatic trafiic signal apparatus which is rugged and which will give long periods of troublefree service.

With the above objects in view, the present invention mainly consists in a traflic signal apparatus which comprises light source means for projecting a light beam, shielding means operatively associated with the light source means for so shielding the same that the light beam emitted thereby is divided into two discrete beams of light, and means operatively associated with the shielding means for varying the distance between the two dis crete beams of light emitted by the light source means.

More particularly, a traffic signal apparatus according to the present invention includes support means, a green light source on the support means for producing a light beam, first screening means formed with elongated slot means, second screening means formed with second elongated slot means along the edges of a substantially rhombic area, one of the screening means being arranged in the path of the light beam, and the other of the screening means being mounted on the support means for moving across the path so that the diagonals of the substantially rhombic area are substantially parallel and normal, respectively, to the first elongated slot means when the other screening means moves across the path, and moving means on the support means for moving the other screening means across the path. As a result, during at least a portion of the first half-cycle of the movement of the other screening means across the path, two discrete beams of light are projected in the direction of the path and the distance between the two discrete beams of light increases, and during at least a portion of the second half-cycle of the movement of the other screening means across the path, the distance between the two discrete beams of light decreases. Preferably, the arrangement of the parts is such that when the two discrete beams of light meet, or at least almostmeet so as to give the illusion as to be one 2 beam of light, the red light is automatically energized.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. l is a longitudinal sectional view of one embodiment of an apparatus according to the present invention;

Fig. 2 is a transverse section of the apparatus shown in Fig. 1 taken substantially along line AA of Fig. 1;

Fig. 3 is the curved cylindrical surface of a part incorporated in the apparatus, as developed in a plane;

Figs. 4, 5 and 6 show different operative positions of the apparatus;

Fig. 7 is an elevational view of the apparatus, partly in section, this figure also showing a wiring diagram, including the switch mechanism, of the red lamp circuit; and

Fig. '8 is a sectional view taken along line B-B of Fig. 7.

Referring now to the drawings, and to Figs. 1 and 2 in particular, there is shown a traffic signal apparatus according to the present invention which includes an elongated light source such as a green fluorescent lamp A having a length of approximately 60 centimeters. The lamp is surrounded by a cylindrical screen C formed with slots B the dimensions of which may be approximately 4 x 55 centimeters. An additional cylindrical screen D which is formed with two sets of four elongated slots, each set defining a rhom'bic area W, as is shown in Fig. 3, surrounds and rotates about the screen C. When the slots are opposite the slots B of screen C, light emitted by the light source A is visible through two lateral transparent or translucent windows. The screen C and the screen D thus act as screening means for shielding the light beam emanating from the light source A, with the screen D being so arranged that it rotates about an axis which coincides with the axis of the lamp A.

The distances X and Y in Fig. 3 are representative of the time lapse which one desires to establish between the green and red lights. Moreover, this time lapse may be adjusted by varying the speed at which the drum D is rotated, and this is accomplished by providing a motor I and a gear box 0. The drum D is carried by support means comprising guides and supports T, and the drum D is driven in such a manner that the green light appears when the end of the rhombic areas coincide with the lateral slot B of the screen C, whereupon the fluorescent light is seen in the center of the screen. Upon continued rotation of the drum, the slots appear to split the light and the resulting two discrete beams of light move from each other while the drum rotates until they reach the ends of the rhombic areas W. The two discrete beams of light will thereupon continue to travel in the opposite direction, i. e., toward each other, until they meet and disappear, as shown in Figs. 4, 5 and 6. At this instant, the contact K of substantially U-shaped cross section enters into the chamber 4 made of insulating material (see below) and containing mercury M. This nected to a source of electrical energy, wire 1 being con,-

nected to the red lamp R and wire 2 being connected to one terminal of the switch mechanism S. A third wire 2' is connected to the other terminal of the switch mech{ anism S and to the red lamp R.

The switch mechanism S includes a receptacle device 4 made of insulating material, which receptacle device is divided into two substantially parallel chambers 5 each of which contains mercury. Terminals 3 and 7 extend through the bottom portion of each of the chambers 5, as is illustrated in the drawing;

Two'arcuate contact elements K are mounted on the drum D. I Each of these contact elements has a U-shaped cross-sectional configuration, the arrangement of the parts'being such that the leg portions of the contact elements K may extend into the chambers 5, respectively, so as to bridge the pools of mercury thereby electrically connecting the contacts 3 and 7 to each other and energizing the red lamp R, It will be understood, therefore, that during rotation of the drum D about its axisgthe red lamp R will be energized at such time as one of the contact elements K bridges the pools of mercury within the chambers 5 which occurs only when the slots of the screens C and of cylinder D are out of alignment with each other. v

It has been found that the most satisfying results are obtained when the drum D is rotated at such a speed that the discrete beams of light appear to move at a rate of approximately 5 centimeters per second, both during separation and rejoining. This gives the observer an opportunity to know exactly how much time is still available before the green light changes to red, so that upon approaching the signal apparatus he will know with certainty whether or not there is still 's'uflicient time left during which to cross the control point at which the apparatus is located.

It has been found practical to cover the entire device by a metallic box which is formed with lateral cutout portions through which the light emitted by the lamp A passes. The cutout portions may be covered by colorless smoked glass or other suitable transparent or translucent sheets.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of trafiic control apparatus differing from the types described above.

While the invention has been illustrated and described as embodied in a tratfic control apparatus wherein the discrete beams of light travel horizontally, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A traflic signal apparatus, comprising, in combination, support means; a light source on said support means for projecting a light beam; first screening means formed with first elongated slot means; second screening means formed with second elongated slot means along the edges of a substantially rhombic area, one of said screening means being arranged in the path of said light beam and the other of said screening means being mounted on said support means for movement across said path so that the diagonals of said substantially rhombic area are substantially parallel and normal, respectively, to said first elongated slot means when said other screening means moves across said path; and moving means on said support means for moving said other screening means across said path whereby during at least a portion of the first half cycle of the movement of said other screening means across said path two discrete beams of light are projected in the direction of said path and the distance between said two discrete beams of light increases and during at least a portion of the second half cycle of the movement of said other screening means across said path the distance between said two discrete beams of light decreases.

2. A trafiic signal apparatus, comprising, in combination, support means; .an elongated light source on said support means for projecting an elongated light beam; first screening means arranged in the path of said light beam and formed with first elongated slot means; cylindrical second screening means formed with second elongated slot means along the edges of a substantially rhombic area and mounted on said support means for rotation about an axis of rotation coincident with the axis of said elongated light source so that the diagonals of said rhombic area are substantially parallel and normal, respectively, to said first elongated slot means when said rhombic area of said second screening means moves across said path; and moving means on said support means for rotating said second screening means about said axis of rotation and thereby moving said rhombic area across said path at a substantially constant rate whereby during the first half cycle 'of the movement of said rhombic area of said second screening means across said path two discrete beams of light are projected in the direction of said path and the distance between said two discrete beams of light increases at a substantially constant rate and during the second half cycle of the movement of said rhombic area of said second screening means across said path the distance between said two discrete beams of light decreases at the last-mentioned substantially constant rate.

3. A 'trafiic signal apparatus, comprising, in combination, support means; an elongated first light source on said support means for projecting an elongated first light beam; first screening means arranged in the path of said first light beam and formed with first elongated slot means; cylindrical second screening means formed with second elongated slot means along the edges of a substantially rhombic area and mounted on said support means for rotation about an axis of rotation coincident with the axis of said elongated light source so that the diagonals of said rhombic area are substantially parallel and normal, respectively, to said first elongated slot means when said rhombic area of said second screening means moves across said path; moving means on said support means for rotating said second screening means about said axis of rotation and thereby moving said rhombic area across said path at a substantially constant rate whereby during the first half cycle of the movement of said rhombic area of said second screening means across said path two discrete beams of light are projected in the direction of said path and the distance between said two discrete beams of light increases at a substantially constant rate and during the second half cycle of the movement of said rhombic area of said second screening means across said path the distance between said two discrete beams of light decreases at the last-mentioned substantially constant rate; a second light source on said support means for projecting a second light beam; and switch means operatively associated with said second screening means and electrically connected to said second light source for energizing the same when said first and second slot means are out of alignment with each other.

4. A traffic signal apparatus, comprising, in combination, support means; a light source on said support means for projecting a light beam; first screening means arranged in the path of said light beam and'formed with first elongated slot means; second screening means formed with second elongated slot means along the edges of two substantially rhombic areas and mounted on said support means for movement across said path so that the diagonals of each respective rhombic area are substantially parallel and normal, respectively, to said first elongated slot means when each respective rhombic area of said second screening means moves across said path; and moving means on said support means for moving said second screening means across said path whereby during at least a portion of the first half cycle of the movement of each respective rhombic area of said second screening means across said path two discrete beams of light are projected in the direction of said path and the distance between said two discrete beams of light increases and during at least a portion of the second half cycle of the movement of each respective rhombic area of said second screening means across said path the distance between said two discrete beams of light decreases.

5. A trafiic signal apparatus, comprising, in combination, support means; an elongated light source on said support means for projecting elongated light beams in opposite directions; first screening means arranged in the paths of said light beams and formed with first elongated slot means; cylindrical second screening means formed with second elongated slot means along the edges of diametrically opposite substantially rhombic areas and mounted on said support means for rotation about an axis of rotation coincident with the axis of said elongated light source so that the diagonals of each of said rhombic areas are substantially parallel and normal, respectively, to said first elongated slot means when each of said rhombic areas of said second screening means moves across each of said paths; and moving means on said support means for rotating said second screening means about said axis of rotation at a substantially constant rate and thereby moving each of said rhombic areas across each of said paths at a substantially constant rate so that one of said rhombic areas moves across one of said paths at the same time the other of said rhombic areas moves across the other of said paths whereby during the first half cycle of the movement of each respective rhombic area across each respective path two discrete beams of light are projected in the direction of each of said paths and the distance between two discrete beams of light projected in the same direction increases at the last-mentioned substantially constant rate and during the second half cycle of the movement of each respective rhombic area across each respective path the distance between two discrete beams of light projected in the same direction decreases at the last-mentioned substantially constant rate.

6. In a trafiic signal apparatus, in combination, light source means for projecting a light beam; shielding means operatively associated with said light source means for so shielding the same that the light beam emitted thereby is divided into two discrete beams of light; and means operatively associated with said shielding means for varying the distance between the two discrete beams of light emitted by said light source means.

References (Jited in the file of this patent UNITED STATES PATENTS 1,749,390 Olafson Mar. 4, 1930 1,827,481 MOSher Oct. 13, 1931 1,829,025 Walker Oct. 27, 1931 1,831,814 Livingston Nov. 17, 1931 2,453,931 Phillips Nov. 16, 1948 

